Solar and HVAC Services in San Marcos, CA

Power a More Comfortable, Energy-Efficient Home With Local HVAC Pros

Need a quick AC repair? Thinking about upgrading your heating system? Curious if solar power could save you money? At Guthrie & Sons Heating, Air & Solar, we’re your all-in-one team for home comfort in San Marcos.

With transparent pricing, skilled service, and no pushy sales, we’ll make sure your home or business stays comfortable — today, tomorrow, and for years to come. Contact us for an estimate!

San Marcos’s Choice for Cooling, Heating, Indoor Air Quality, and Solar Services

Whether you’re catching the breeze near Double Peak Park or settling in by Lake San Marcos, Guthrie & Sons is here to keep your home or business running just right with expert HVAC, indoor air quality, and solar services.

From upgrading your home’s outdated AC to maintaining your heater's performance, we're your trusted team for installation, repair, maintenance, and replacement services. Seeking cleaner air or considering solar? We also offer indoor air quality solutions and solar services — all under one roof! Whether it’s older homes near Palomar College or newer builds around Discovery Lake, we’re ready to help.

At Guthrie & Sons, we’re more than a business — we’re a family legacy. Passed down through generations, our company is built on trust, care, and a commitment to doing things the right way. That means when you call us, you get the family treatment — genuine care, honest solutions, and no pushy sales.

And with NATE-certified technicians who are truly the best in the business, you can expect five-star service every time. Contact us today — we’re ready to help!

The Guthrie Way

Service Backed by Integrity, Experience, and Family Values

As a family-owned company with our name on the line, we take great pride in our work. That means we do things the Guthrie Way. Here’s what you can expect when you call us for service:

5-Star Service

We take pride in setting the gold standard for HVAC service in the local area. Our dedicated team of experts is committed to delivering nothing less than 5-star service in every aspect of our work. Your comfort is our commitment.

Honest Pricing

When we say no hidden fees, we mean it. Our pricing is upfront and transparent, with no fine print or gimmicks. Before we get to work, we’ll walk you through your options and give you a clear breakdown of the costs.

Expert Technicians

Not all technicians are created equal. Ours are NATE-certified — the highest standard in the industry. Whether it’s a simple repair or a complex installation, we bring experience and expertise to every home we enter.

Family Values

We’ve been family-owned and operated for generations, and we treat every customer like one of our own. We’re proud to bring personal care and dedication to every job. When you call us, you’re not just getting a service — you’re becoming part of the Guthrie family.

No Upsells

We’re not here to sell you what you don’t need. Our job is to find the best solution for you, not our bottom line. You can always count on our team for honest recommendations that prioritize your needs and your budget.

Protect Your Home and Wallet With Our USA Membership Plan

Your comfort, health, and safety are our priorities, and we know that a reliable heating and cooling system is key to all three. While plenty of San Marcos HVAC companies offer maintenance plans, our USA Membership Plan goes further to better meet your needs and save you money.

Regular maintenance is the best way to avoid costly repairs and keep your system running longer. We’ll reach out when it’s time for service in San Marcos, so you never miss a tune-up, even with your busy schedule. As a member, you’ll enjoy repair discounts, lower service call fees, and priority scheduling. Talk to your technician about signing up, or give our office a call to learn more!

Maintenance Plans

Budget Concerns? We Offer Flexible Financing for Your Comfort Needs

Nobody plans for a heating or cooling system to fail, but when it happens, Guthrie & Sons has options to help make investing in new equipment more affordable. Our flexible financing options help you get the heating and cooling system you need now while paying over time. Ready to explore your options? Call us at (619) 269-3013 — we’ll walk you through everything.

Learn More About Financing

Air Conditioning Services in San Marcos

Trust Guthrie & Sons for top-notch air conditioning services in San Marcos, keeping your space comfortably cool. Upgrade to an energy-efficient system with us and enjoy valuable tax incentives and rebates. We'll guide you through the process of finding and applying for these savings.

Air Conditioning Installation

Guthrie & Sons is a specialist in air conditioning installation for new builds and homes lacking AC in San Marcos. We excel in creating custom systems that fit your space, boost energy efficiency, and maintain a cool home. We manage everything from ductwork to system selection.

Air Conditioning Maintenance

Ensure your system's longevity and avoid expensive malfunctions with our air conditioning maintenance in San Marcos. Our skilled technicians conduct AC tune-ups, enhancing efficiency and prolonging your air conditioner's lifespan.

Air Conditioning Repair

If your AC is struggling, making strange noises, or refusing to turn on, it's time for professional air conditioning repair in San Marcos. At Guthrie & Sons, we use advanced tools and our extensive experience to diagnose and fix issues swiftly.

Air Conditioning Replacement

Does your air conditioning unit, over a decade old, require constant repairs? Considering an air conditioning replacement may be a wise decision. Our team will assist you in selecting an energy-efficient system that not only provides superior cooling but also reduces your energy costs.

Mini Split Services in San Marcos

Looking for a smarter way to heat and cool your San Marcos home? A ductless mini split system gives you zoned comfort and better energy efficiency — perfect for adjusting temperatures room by room. Whether you’re near Cal State San Marcos or tucked into one of the older neighborhoods with tricky attic spaces, we’ve helped homeowners across the area get more from their systems. From new installations to ongoing maintenance, Guthrie & Sons delivers ductless mini split solutions you can count on.

Mini Split Installation

Ductless mini splits are ideal for managing the temperature in areas such as refurbished garages, sunlit rooms, or guest quarters, without the heavy-duty work associated with duct installation. We tailor and set up ductless mini split systems that cater to your specific needs.

Mini Split Maintenance

Living by the sea, dealing with dust, and just regular use can wear down your system, particularly in our seaside environment. Our maintenance service for ductless mini splits involves thoroughly cleaning filters, monitoring refrigerant amounts, and examining electrical parts.

Mini Split Repair

If your ductless mini split isn't warming or cooling as it should, shows errors, or operates inconsistently, a repair can solve it. We'll swiftly pinpoint problems like refrigerant leaks, electrical glitches, or defective sensors, restoring your comfort quickly.

Mini Split Replacement

When your mini split system struggles, needs frequent repairs, or raises your electricity bills, consider replacing it with a new ductless mini split. We'll evaluate your existing unit and suggest an energy-saving model suitable for San Marcos's climate.

Heat Pump Services in San Marcos

Seeking an eco-friendly solution for your home's heating and cooling needs? Heat pumps, offered by Guthrie & Sons, efficiently manage temperature by transferring heat in and out of your home, eliminating the need for separate systems. Our comprehensive heat pump services in San Marcos cover installation, maintenance, repair, and replacement, ensuring your home stays comfortable all year round.

Heat Pump Installation

Installing a heat pump is a wise decision for homeowners in San Marcos who desire effective heating and cooling without the trouble of having distinct systems. We'll evaluate your home's design, insulation, and energy requirements to suggest the perfect unit.

Heat Pump Maintenance

Even in moderate climates, heat pumps are constantly working, necessitating regular maintenance. We advise conducting semi-annual heat pump maintenance check-ups. These inspections will assess refrigerant levels, clean the coils, and verify that all components are operating correctly.

Heat Pump Repair

Over time, with regular use, heat pumps may develop issues. These could be poor airflow, inconsistent cooling, or unusual sounds. We diagnose these issues swiftly, identifying problems like refrigerant leaks, electrical faults, or sensor issues.

Heat Pump Replacement

If your system constantly needs repairs or has stopped working, a new heat pump can save time, money, and stress. Older units lose efficiency, increasing energy bills. We'll install a new, high-efficiency system for comfort and cost control.

HVAC Services in San Marcos

Whether your home relies on a single unit or a full HVAC system, we’re here to keep it all running smoothly. From ACs and furnaces to heat pumps, our expert HVAC services in San Marcos are tailored to meet the needs of homes throughout the area. From the neighborhoods surrounding Woodland Park to communities near Rancho Santa Fe Road, you can trust our experienced team to help.

HVAC Installation

Installing a new HVAC system isn't simply about selecting a model — it's about finding the perfect match for your home. We meticulously assess your space, considering size and ventilation needs, to recommend the best heating and cooling solution for sustained comfort.

HVAC Maintenance

Ignoring HVAC maintenance is like neglecting car oil changes — it's only a matter of time before issues crop up. We follow manufacturer guidelines and our checklist to identify minor problems early and keep your system robust.

HVAC Repair

Odd sounds, poor air circulation, or spaces that don't get warm or cool properly? These are signs that your HVAC system needs attention. Delaying can transform a small repair into a significant malfunction. We act promptly, identify the issue, and perform professional HVAC fixes.

HVAC Replacement

Overwhelmed by continuous repairs and rising energy bills? It may be time for an HVAC replacement. We work quickly to install your replacement with minimal disruption. After it's operational, we'll instruct you on its use and provide maintenance tips.

Heating Services

We’ve been helping San Marcos homeowners stay comfortable for years — especially when the temperatures drop. Our expert heating services make it easy to keep your home warm during those cool San Marcos mornings and evenings. Whether you rely on a furnace, heat pump, or mini split, we’ll keep your system running at its best. From installation and maintenance to repairs and replacements, we’re here to make sure your home stays cozy year-round.

Heating Installation

Looking to heat your home? Our team is ready to assist you in choosing the perfect heating solution. Whether it's a furnace, heat pump, or mini split, we'll explain your options and install a durable system that's built to last.

Heating Maintenance

Your heating system requires more than a simple air filter replacement to remain in prime condition. When you reach out to us for heating upkeep, we'll meticulously clean, examine, and adjust every component. This translates to fewer system failures, reduced energy expenses, and significantly enhanced comfort levels.

Heating Repair

If your heater’s blowing cold air, making strange noises, or just not keeping up, it’s time to bring in the pros. We’ll quickly find the issue, walk you through the fix, and get the warmth flowing again. No runaround, no pressure — just honest, reliable repairs that get your heat back on track.

Heating Replacement

If your heater is nearing its end, replacing it doesn't need to be difficult. We'll guide you in choosing a system that's efficient, reliable, and fits your home. After installation, we'll test it, make adjustments, and show you how to keep it running smoothly.

Furnace Services in San Marcos

Furnaces remain one of the most popular and effective ways to heat homes in San Marcos — and we’re here to make sure yours runs at its best. Whether you’re installing a new unit, maintaining an older system, or exploring an upgrade, our expert furnace services will keep your home warm and comfortable all winter long. We provide fast, dependable service throughout the area, including neighborhoods near Bradley Park and the San Marcos Historical Society.

Furnace Installation

Getting the right furnace for your home matters. Too big, and it’ll cycle on and off constantly — wasting energy and wearing out faster. Too small, and it won’t keep you warm when it counts. We’ll assess your home’s needs and install a properly sized furnace that delivers comfort, efficiency, and long-term performance.

Furnace Maintenance

Schedule a yearly furnace check-up, ideally before winter, to ensure your system runs safely and efficiently. Our furnace maintenance service includes cleaning burners, inspecting the heat exchanger, checking for gas leaks, and testing all safety controls.

Furnace Repair

Odd sounds, poor air circulation, and chilly rooms that just won't heat up could all point to a possible need for a furnace fix. If your system is pumping out cold air or refusing to start, our HVAC experts are ready to act fast to restore your warmth.

Furnace Replacement

If your heating system is beyond repair or too costly to operate, considering a furnace replacement is often the best solution. We manage all the details — from safely removing the old unit and disposing of it, to expertly installing your new, energy-efficient furnace.

Indoor Air Quality Services in San Marcos

It’s easy to take pride in San Marcos with places like the Antique Village and the vibrant Farmer's Market just down the street. We make certain your home’s air is just as fresh as San Marcos's outside air. We effectively combat the build-up of dust, allergens, and pollutants, and tackle issues related to humidity and poor ventilation.

From the installation of air purifiers to dehumidifiers, our expert team provides efficient installation, repair, and maintenance services. We're committed to enhancing your indoor air quality, ensuring you breathe easier and live healthier.

Air Purifier Installation

Want cleaner, healthier air in your home? Installing an air purifier is a wise decision. We install whole-home air purifiers that trap dust, allergens, and airborne contaminants.

Air Purifier Repair

When your air purifier isn't functioning properly, it might be time for a repair. From blocked filters to electrical glitches, we troubleshoot and fix problems swiftly, ensuring clean air circulation.

Dehumidifier Installation

If your house feels damp due to high humidity, installing a dehumidifier can restore balance. We'll help choose and install the perfect system for your area.

Dehumidifier Repair

When your system isn't managing humidity properly, it's time for a dehumidifier fix. We tackle problems such as leaks in the refrigerant, malfunctioning sensors, and issues with drainage.

Duct Sealing

Duct leaks can result in poor air quality, excess energy use, and higher expenses. Our duct sealing service identifies and repairs these leaks, ensuring clean, conditioned air circulates correctly.

Media Air Cleaner Installation

If you're concerned about allergies in your home, installing a media air cleaner can offer better filtration. We install media cleaners that capture even the smallest particles.

UV Air Cleaner Installation

UV air cleaner installation introduces a robust defense against airborne germs and allergens. We position these UV air cleaners inside your ducts, neutralizing bacteria, viruses, and mold effectively.

UV Light Installation

Prevent mold and bacteria in your HVAC system with a UV light. We install these lights near your coils. As air passes through, it's sterilized, maintaining a cleaner system.

Home Safety & Comfort Controls

San Marcos homeowners know that comfort isn’t just about temperature — it’s about safety, control, and peace of mind. When your systems don’t work right, it’s more than inconvenient. Whether it’s a busy day at the San Marcos Library or a quiet evening near Hollandia Park, we’re here to keep your home safe and comfortable.

We offer safety and control services in San Marcos to make your home feel smoother, safer, and more dependable from the inside out. From the bustling areas near Creekside Marketplace to the peaceful corners of Richmar, we’re committed to enhancing your home’s safety and comfort.

CO Detector Installation

Having a CO detector set up in your home safeguards you from the harmful effects of carbon monoxide. We put trustworthy detectors in crucial spots to offer round-the-clock surveillance.

Thermostat Installation

Proper thermostat installation can enhance comfort and decrease energy usage. We specialize in installing smart or programmable thermostats, helping you save money.

Thermostat Repair

If your house seems too warm or too chilly, the problem might be with a broken thermostat. Reach out for a thermostat fix to sort out issues with temperature and connection.

Thermostat Replacement

Old-fashioned or untrustworthy thermostats can lead to discomfort and higher energy expenses. We're here to suggest and set up a version that offers improved regulation and effectiveness.

Solar Services in San Marcos

Make the most of San Marcos's endless sunshine with our expert solar services. At Guthrie & Sons, we specialize in solar panel installation, battery backup systems, and EV charger solutions, all designed to cut down your energy bills and reduce grid dependency. Investing in solar not only provides clean, renewable energy but also shields you from rising utility costs. It's a savvy, long-term investment, and we're committed to guiding you through every step of the process.

Heat Pump Water Heater Services in San Marcos

Experience energy-efficient comfort at your home with Guthrie & Sons' heat pump water heater installation services in San Marcos. Unlike traditional heaters, our systems utilize ambient air to produce heat, drastically cutting down on energy consumption and reducing your carbon footprint. This means you get reliable hot water, lower utility bills, and a more eco-friendly home. All of this is backed by our dedicated and knowledgeable team who ensure everything runs smoothly and efficiently.

Frequently Asked Questions

Yes! We provide free estimates on replacements for heating, air conditioning, and solar systems. Our team will assess your needs, explain your options, and offer clear pricing — no pressure, no gimmicks. You’ll know exactly what to expect before making a decision.

Absolutely. Our technicians are background-checked and committed to your safety and satisfaction. We only hire qualified, experienced professionals who meet our high standards. With Guthrie & Sons, you’re in trusted hands.

We understand that comfort can’t wait. In most cases, we offer same-day or next-day service, depending on availability. Just give us a call, and we’ll find a time that works for you.

Yes, we handle all necessary permits for your HVAC or solar installation. From navigating local regulations to submitting paperwork, we make sure everything is done by the book. You won’t have to worry about a thing.

Real Reviews From Real Customers

We do things differently, and our customers appreciate it. See what some of our thousands of satisfied customers have to say about working with us.

Phil Lane

17:18 10 May 25

Guthrie and Sons has provided great service. There are many HVAC companies in San Diego to choose from. They provided a very reasonable estimate for replacing our two AC systems. Once we said yes installation happened within days. It was a quality install. They answer the phone quickly when I've had questions. Happy to refer them to others.

Dianne Haase

20:57 02 May 25

Great customer service, technicians always on time and friendly. I’ve had my new hybrid heat pump for a few years and Guthrie & Sons are very proactive making sure everything is running smoothly. Very happy in my decision to use them!

Andrea Kossoudji

01:11 30 Apr 25

Great service!! Jonathan was patient, kind, knowledgeable and extremely professional! I love Guthrie & Sons’ reminder system, notification of the technician enroute, the easy invoice system and immediate emailing of the findings, including detailed photographs of the work completed!! Highly recommend!

james beedon

20:47 23 Apr 25

Last summer my air conditioner couldn't cool the house in the hottest period of summer. The HVAC team I was working with came in and said the coils were leaking, the unit was 20 years old. I requested quotes from 5 different companies, and the variation of prices was huge. I went with Guthrie and Sons for these reasons:1. Local Company2. Family Owned3. Great presentation, no pressure4. Good products5. Competitive pricingJust installed yesterday, so jury is still out on the system, but installation was thorough and great communication so far!

Darius Degher

21:45 22 Apr 25

Carson and Michael were brilliant. The heat pump installation went smoothly, and they are really pleasant and trustworthy fellows. The day after it was installed, I had a plumber at my house. He looked at their work and was impressed. He said it was much cleaner than the way HVAC people usually do it.

Lito Ricasata

19:03 08 Apr 25

First time prospective client of Guthrie and Sons. Very responsive staff in providing updates on my calls. Mario F. came over to check out my existing cooling and heating system and is very thorough and professional in providing necessary information related to repair/upgrades. Pending his quote, my experience with Guthrie and Sons is top notch and most highly recommended.Updated review: Kareen, Daniel and Michael worked on the AC replacement, relocation of furnace to the attic and replacement of ductwork. Very professional and knowledgeable team in my opinion. Completed the work in a timely and very satisfactory manner.

Michael Myers

00:19 25 Mar 25

My experience with Guthrie & Sons has been excellent, and I am pleased to write a very favorable review about it. They replaced three air conditioners and three propane furnaces with new equipment that utilizes heat pump technology. I had met with other companies and I was close to coming to a conclusion, when a friend recommended Guthrie & Sons. He told me that they are hyper focused on customer service from beginning to end.Their customer service started with the on line completion of a basic information form. Shortly after submitting that form, I heard from Zach who scheduled an appointment at my home.I had already met with three other HVAC contractors, and for that reason, I had some basic information about the systems available and how heat pumps work and whether propane furnaces should also be installed. I signed a contract on a Friday. By Wednesday of the next week they had completed the installation. Wow.The installation of one of the furnaces in the attic caused minor damage to the drywall. THEY BROUGHT IT TO MY ATTENTION and told me a drywall contractor would be in touch regarding its repair. Two days later it was repaired.Since installation, the equipment (heat pumps from Bosch) has been working great and I am optimistic about the future. Meanwhile, their pricing, warranty and terms are far superior to their competitors.Since this is an unusually long review and so favorable, let me add this: This is my honest, uncompensated opinion. I have no relationship with anyone at Guthrie & Sons other than the contract we executed.

Tom H

15:21 20 Mar 25

We recently had Guthrie and Sons install a Mini-Split system in our home. The entire process was handled professionally with no issues occurring at any time. The estimator (Vlad) went through options with us but let us evaluate the best solution for us with zero pressure. The installation team (Matthew and Aaron) showed up on time, reviewed the scope of the job, made sure they understood what we wanted, and then proceeded to complete the installation exactly as discussed. They asked for my input as needed so there were no surprises when the job was completed.They respected my property and made sure everything was left at least as clean was when they arrived. The job was completed on time and as promised and they reviewed the details of the system and its use clearly. I would definitely have Guthrie and Sons do other electrical/HVAC work should the need arise.

Mike Macias

19:43 19 Mar 25

I have been in the construction industry in San Diego for over 50 years. I owned my own contracting company for over 40 years. I have seen all levels of customer service in my years. The level of customer service from Guthrie and Son’s is among the best I’ve ever seen and received. Every time I hear anyone asking for a referral for HVAC work I immediately give them your number. When I recommend a company I in essence am putting my name and reputation on the line. I refer them with 100% confidence in the service they will receive. Thank you very much for your legendary service.

Scott Sypkens

23:32 11 Mar 25

We first hired Guthrie and Sons to replace a furnace after comparing proposals from several heating and air companies. They’ve since been back for annual check ups, and today Kareen came to diagnose and resolve an issue with our mini-splits. My experience each time, including today, is that they hire friendly, knowledgeable people who do good work. They’ve never tried to upsell or do anything unnecessary, which is the way it should be. I’d recommend them to anyone who asks.

Marilyn Rivas

20:07 09 Mar 25

They always come out quickly. They are so polite and careful.

Steven Wheeler

19:28 07 Mar 25

Good technician did everything right yet our heater still not workingJonathan gave us the likeliest problems so we’ll have to get it fixed

Dmitriy

04:01 07 Mar 25

My AC was not working for seven months. Three other companies tried to fix it with no success. Don’t make the same mistake I did—go straight to Guthrie & Sons! They are absolutely worth every penny.

Cecilia Benevich

22:17 05 Mar 25

Rick

21:38 05 Mar 25

Experienced technician gave me the particulars of a replacement HVAC system

Daylan Dauchot

21:28 05 Mar 25

Courteous, in-time, helpful, honest. Would recommend.

Xinxin Wang

22:05 04 Mar 25

Tom Barden

18:26 04 Mar 25

Adair Cooke

19:02 03 Mar 25

Jonathon is a great technician. He is very willing to answer any questions and explains things very well. He is very transparent with letting us know cost, finance options, different furnace models and anything else we want to know. I would highly recommend him to anyone looking for furnace repair or replacement.

Bratso Krsic

00:29 28 Feb 25

Guthrie and Sons took on the challenging project of installing an HVAC system at St. George's Serbian Orthodox Church of San Diego, CA. They were the only company among the six we consulted that saw the project through to the end. The members of our congregation are not just happy, but thoroughly satisfied with the heating and air conditioning. The system, split units/floor units with condensers outside, was installed with minimal intrusion onto the church's artwork. Despite the project taking longer than expected due to permit delays, the results were well worth the wait. We highly recommend Guthrie and Sons Heating and Air.

Schedule Service With Guthrie & Sons Today

At Guthrie & Sons Heating, Air & Solar, we don’t just show up — we show that we care. Whether your home needs a cooling upgrade, a reliable heater, or energy-saving solar solutions, we’re dedicated to providing service that puts you first.

With free estimates, upfront pricing, and flexible financing, we make repairs and upgrades more affordable. And when we’re done, we’ll leave your space just as we found it — only now it’s more comfortable and energy efficient, which means it feels great and is saving you more money. Now that’s a win-win!

Use our website or call (619) 269-3013 to schedule heating, air conditioning, or solar services in San Diego, California, with Guthrie & Sons Heating, Air & Solar.

8248 Ronson Road
San Diego, CA 92111

(619) 269-3013